1. Field of the Invention
This invention relates generally to retrieval of prerecorded sound patterns, and more particularly to a method and apparatus for retrieving one or more sound patterns stored in memory, such as RAM or ROM, in synchronization with a portion of music at any point in the music.
2. Description of the Relevant Art
Various types of electronic organs and keyboards have been seen over the years, as well as various types of digital sound processors. One area of interest to some users is the ability to take a song, or a basic repeating pattern, and superimpose an additional pattern on top of the song. While the prior art devices known to Applicant are in some ways capable of adding one of a plurality of patterns to an underlying "song," one common problem is that it is difficult to synchronize the pattern with the underlying song, particularly where the pattern chosen to be added to the song may be of any length.
It is believed that electronic organs and keyboards solve this problem by limiting both the underlying "song" and the additional pattern to be added so that each is a measure which is continuously repeated. Thus, the device need merely wait until the end of a measure to begin adding the desired pattern, and the pattern will always be synchronous with the underlying "song" or pattern. The user typically then adds additional notes through an input device such as a piano-style keyboard.
This type of device limits the addition of the pattern to the beginning of a measure. It is also believed that another limitation of these devices is that the entire measure must be stored somehow in order to be continuously retrieved. To store an entire song, and several patterns which might be added to the song would take an enormous amount of memory.
The present invention avoids these deficiencies and allows the user to define both an underlying song and one or more sound patterns to be added to the song of any length, with a minimum amount of memory needed to store them, and to begin adding the pattern synchronous with the song at any time during the song.